It's been hailed as one of the most important and stunning discoveries of the century: tiny archaic humans that lived among us until only 13,000 years ago, isolated on an Indonesian island. According to the Australian and Indonesian researchers who made the discovery, first reported in Nature, the seven individuals found on the island of Flores, each no more than three and a half feet high, are a smaller version of Homo erectus.

For Susan Antón, a New York University anthropologist who has worked in Indonesia and is an expert on H. erectus, it was the size, not the age, of the Floresians that really raised an eyebrow. Anton's own work has shown that H. erectus survived in Indonesia until 25,000 years ago--still relatively recent, but she's never encountered H. erectus remains of such a size. "My intial reaction was, 'Well, maybe its a small human. Modern humans are highly variable as well. In tropical rain forests, for instance, you have pygmy humans. But [in terms of H. erectus] this really isn't what we've seen before--even the later surviving H. erectus in Indonesia are quite large."

Other scholars are questioning the H. erectus identification, pointing to the sophisticated stone tools found with the remains. The tools look as if they were made by modern humans, the argument goes, while the tiny Floresians had an equally diminutive brain capacity, smaller than that of a chimpanzee.

"I wrote a big overview of H. erectus a year ago, and I ended it by saying that the size issue still need to be investigated," adds Antón. "I guess I was pretty prescient."

But it may be impossible to settle the matter of who the Floresians were by taking a closer look at the bones. According to Stanford archaeologist Richard Klein, skull morphology, or shape, is insufficient evidence for determining whether they were derived from Homo erectus or Homo sapiens. With luck, the debate could be resolved by DNA analysis. The age of the remains does not preclude survival of replicable DNA in the bones, although Indonesia's warm climate might adversely affect the chances that it is intact.